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Vishay General Semiconductor - Diodes Division SMCJ78HE3/57T
- Part No.:
- SMCJ78HE3/57T
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ78HE3/57T.pdf
- Description:
- TVS DIODE 78VWM 139VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:8,526
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Product details
Overview
SMCJ78HE3/57T from Vishay General Semiconductor is a unidirectional transient voltage suppressor (TVS) diode in DO-214AB (SMCJ) package, designed for robust overvoltage protection of DC power rails and signal lines. It features a 78 V stand-off voltage (VWM), 86.7–95.8 V breakdown voltage (VBR) at 1 mA, 1500 W peak pulse power (10/1000 µs), clamping voltage of 126 V at 11.9 A, and AEC-Q101 qualification for automotive-grade reliability.
For engineers reviewing the SMCJ78HE3/57T datasheet, SMCJ78HE3/57T pinout, SMCJ78HE3/57T application, or SMCJ78HE3/57T equivalent, key selection criteria include clamping performance under 10/1000 µs surge, junction temperature derating above 25 °C, unidirectional polarity marking, and compatibility with automated SMT placement on 8.0 mm × 8.0 mm copper pads.
Technical Context
The SMCJ78HE3/57T operates as a silicon avalanche diode, leveraging glass-passivated junction technology to achieve sub-nanosecond response time and low incremental surge resistance. Its unidirectional configuration enables integration into DC-biased circuits where reverse conduction must be blocked until clamping threshold is exceeded.
Thermal design relies on junction-to-lead thermal resistance of 15 °C/W and junction-to-ambient of 75 °C/W, with maximum operating junction temperature rated at +150 °C. Derating curves confirm usable peak pulse power drops to ~75% at TA = 100 °C, requiring layout-aware thermal management for sustained surge events.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78 V - Maximum continuous reverse operating voltage before leakage exceeds 1 µA; defines safe DC bias margin. |
| VBR min/max | 86.7 V / 95.8 V at IT = 1 mA - Ensures consistent avalanche initiation across production lots; tight 10.5% tolerance supports predictable clamping. |
| VC @ IPPM | 126 V at 11.9 A - Clamped voltage during 10/1000 µs surge; limits downstream IC stress to ≤126 V under full-rated transient. |
| PPPM | 1500 W - Peak pulse power handling capability; validates protection against IEC 61000-4-5 Level 4 surges (4 kV line-earth). |
| TJ max | +150 °C - Enables operation in under-hood automotive environments and industrial enclosures without forced cooling. |
| AEC-Q101 | Qualified - Confirms reliability for automotive electronics per stress test requirements including HTGB, HTRB, and TCT. |
Pinout & Package
Package: DO-214AB (SMCJ), surface-mount, low-profile case with matte tin-plated leads solderable per J-STD-002 and JESD 22-B102. Polarity indicated by cathode band; unidirectional operation requires correct orientation relative to DC bias.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry point | Connected to lower-potential side of protected circuit (e.g., GND or return path); conducts only during forward surge or bias. |
| Cathode | Avalanche clamping node | Connected to higher-potential rail (e.g., 78 V supply); initiates clamping when reverse voltage exceeds VBR; marked with band. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Enables stable VBR over lifetime and high humidity resistance; eliminates risk of junction corrosion in automotive under-hood conditions. |
| MSL Level 1 (260 °C peak) | Supports lead-free reflow without popcorn effect or delamination; compatible with standard JEDEC J-STD-020 profiles. |
| Low incremental surge resistance | Minimizes voltage overshoot during fast transients; ensures VC remains within 126 V even under 11.9 A 10/1000 µs pulses. |
| JESD 201 Class 2 whisker resistance | HE3 suffix confirms compliance with stringent tin whisker mitigation for long-term reliability in high-reliability systems. |
Applications
| Automotive Power Rail Protection | Industrial Sensor Signal Line Protection |
|---|---|
Use Scenario: Protecting 78 V battery-fed ECUs (e.g., ADAS camera modules) against load dump and alternator transients per ISO 7637-2 Pulse 5a. IC Role / Device Role / Timing Role: Unidirectional TVS placed between 78 V supply and ground, clamping surges before they reach LDOs and microcontrollers. Use Value: Limits voltage seen by downstream 80 V-rated regulators to ≤126 V, preventing latch-up and permanent damage during 1500 W transients. |
Use Scenario: Safeguarding analog output lines (e.g., 4–20 mA current loop transmitters) in factory automation PLC I/O modules. IC Role / Device Role / Timing Role: TVS connected across signal and return paths to shunt ESD and inductive switching spikes induced by solenoid drivers. Use Value: Maintains signal integrity by clamping transients to 126 V while adding <1 pF junction capacitance, avoiding bandwidth degradation. |
| Telecom DC Power Input Protection | Computer Peripheral USB Power Switch Protection |
Use Scenario: Securing 78 V DC input of remote radio units (RRUs) exposed to lightning-induced surges on outdoor cabling. IC Role / Device Role / Timing Role: Primary surge suppression stage upstream of DC-DC converters, absorbing energy before secondary TVS or MOV stages. Use Value: Handles 1500 W single-event surges without degradation, enabling compliance with IEC 61000-4-5 Ed.3 Class 4 immunity testing. |
Use Scenario: Protecting USB Type-C PD controller power switches (e.g., MP6908) fed from 78 V intermediate bus in docking stations. IC Role / Device Role / Timing Role: Unidirectional clamp across switch drain-source to prevent avalanche failure during inductive turn-off spikes. Use Value: Clamps voltage to 126 V within nanoseconds, keeping MOSFET VDS below 150 V rating and eliminating need for oversized RDS(on) devices. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ78AHE3/52T | Lower PPPM (600 W), same VWM (78 V), SMB package (smaller footprint, higher RθJA = 110 °C/W) | Restricted to lower-energy transients (e.g., IEC 61000-4-2 ESD only); unsuitable for ISO 7637-2 load dump. | Select when board space is constrained and surge energy is limited to ≤600 W. |
| SMCJ78A-E3/57T | Same electrical specs but commercial-grade (E3 suffix), not AEC-Q101 qualified; identical DO-214AB package and pinout. | Lacks automotive qualification; acceptable for industrial/commercial designs without automotive reliability requirements. | Choose for cost-sensitive non-automotive applications where AEC-Q101 is not mandated. |
Compared with SMCJ78HE3/57T, SMBJ78AHE3/52T trades surge capacity for compactness, while SMCJ78A-E3/57T offers identical protection without automotive qualification-enabling trade-offs between reliability assurance, physical size, and cost.
Availability
SMCJ78HE3/57T is available at Aetrix Electronics and suitable for automotive ECUs, industrial sensor interfaces, telecom power inputs, and computer peripheral protection requiring stable component supply and AEC-Q101 assurance.
Supply support for SMCJ78HE3/57T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Vishay General Semiconductor is a global leader in discrete semiconductors, specializing in diodes, rectifiers, MOSFETs, and protection devices with emphasis on reliability, efficiency, and application-specific optimization.
The SMCJ series targets high-energy transient suppression in harsh environments; the HE3 variant extends this to automotive-grade applications via AEC-Q101 qualification and enhanced whisker resistance.
FAQ
What is the clamping voltage of the SMCJ78HE3/57T under a 10/1000 µs surge?
The SMCJ78HE3/57T clamps to a maximum of 126 V at its rated peak pulse current of 11.9 A under a 10/1000 µs waveform. This value is measured per ANSI/IEEE C62.35 and verified across production lots; it defines the upper voltage limit imposed on protected circuitry during standardized surge events. The SMCJ78HE3/57T maintains this clamping performance with minimal variation due to its tightly controlled VBR range (86.7–95.8 V).
Is the SMCJ78HE3/57T suitable for automotive applications?
Yes, the SMCJ78HE3/57T is AEC-Q101 qualified and specifically designed for automotive use. Its HE3 suffix denotes compliance with JESD 201 Class 2 whisker testing and RoHS standards, and it meets MSL Level 1 for lead-free reflow. The SMCJ78HE3/57T is deployed in engine control units, ADAS modules, and body electronics where protection against load dump and ISO 7637-2 transients is required.
How does the SMCJ78HE3/57T differ from the SMCJ78A-E3/57T?
The SMCJ78HE3/57T and SMCJ78A-E3/57T share identical electrical specifications and DO-214AB packaging, but differ in qualification: SMCJ78HE3/57T carries AEC-Q101 qualification and JESD 201 Class 2 whisker resistance, whereas SMCJ78A-E3/57T is commercial-grade only. The SMCJ78HE3/57T is intended for automotive and high-reliability industrial use, while the SMCJ78A-E3/57T serves cost-sensitive non-automotive designs.
What is the thermal resistance of the SMCJ78HE3/57T, and how does it affect layout?
The SMCJ78HE3/57T has a typical junction-to-lead thermal resistance (RθJL) of 15 °C/W and junction-to-ambient (RθJA) of 75 °C/W when mounted on 8.0 mm × 8.0 mm copper pads per terminal. To maintain TJ ≤ 150 °C during repeated surges, PCB layout must provide adequate copper area and minimize trace length to thermal planes. Derating curves show >25% power loss above 100 °C ambient, so thermal design is critical in enclosed automotive or industrial enclosures.
Does the SMCJ78HE3/57T have polarity marking, and how is it oriented in-circuit?
Yes, the SMCJ78HE3/57T is unidirectional and features a cathode band marking on the DO-214AB package. During installation, the banded end connects to the higher-potential node (e.g., 78 V rail), while the anode connects to ground or lower potential. Incorrect orientation prevents clamping action and may cause catastrophic failure under reverse surge; the SMCJ78HE3/57T must be placed with polarity verified per assembly drawings.
SMCJ78HE3/57T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AB, SMC
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 78V
- Voltage - Breakdown (Min):
- 86.7V
- Voltage - Clamping (Max) @ Ipp:
- 139V
- Current - Peak Pulse (10/1000µs):
- 10.8A
- Power - Peak Pulse:
- 1500W (1.5kW)
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AB (SMCJ)
SMCJ78HE3/57T FAQ
1.How can I place an order for SMCJ78HE3/57T through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ78HE3/57T on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for SMCJ78HE3/57T reliable?
The price and inventory of SMCJ78HE3/57T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ78HE3/57T is usually 5 days.
3.What payment methods are accepted for SMCJ78HE3/57T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ78HE3/57T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ78HE3/57T?
SMCJ78HE3/57T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ78HE3/57T order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for SMCJ78HE3/57T?
For technical support, including SMCJ78HE3/57T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ78HE3/57T requirements.
6.How does Aetrix verify that SMCJ78HE3/57T is sourced from the original manufacturer or authorized distributors?
All SMCJ78HE3/57T products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that SMCJ78HE3/57T meets industry standards.
7.What is the process for return or replacement of SMCJ78HE3/57T?
All SMCJ78HE3/57T units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ78HE3/57T, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The SMCJ78HE3/57T part is unused and in its original packaging.
Return procedure for SMCJ78HE3/57T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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